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        <h2>
          <span class="refentrytitle">envlpx</span>
        </h2>
        <p>envlpx — 
      Applies an envelope consisting of 3 segments.
    </p>
      </div>
      <div class="refsect1">
        <a id="idp100938208"></a>
        <h2>Description</h2>
        <p>
      <span class="emphasis"><em>envlpx</em></span> -- apply an envelope consisting of 3 segments:
      </p>
        <div class="orderedlist">
          <ol class="orderedlist" type="1">
            <li class="listitem">
              <p>stored function rise shape</p>
            </li>
            <li class="listitem">
              <p>modified exponential pseudo steady state</p>
            </li>
            <li class="listitem">
              <p>exponential decay</p>
            </li>
          </ol>
        </div>
        <p>
    </p>
      </div>
      <div class="refsect1">
        <a id="idp101017072"></a>
        <h2>Syntax</h2>
        <pre class="synopsis">ares <span class="command"><strong>envlpx</strong></span> xamp, irise, idur, idec, ifn, iatss, iatdec [, ixmod]</pre>
        <pre class="synopsis">kres <span class="command"><strong>envlpx</strong></span> kamp, irise, idur, idec, ifn, iatss, iatdec [, ixmod]</pre>
      </div>
      <div class="refsect1">
        <a id="idp101020816"></a>
        <h2>Initialization</h2>
        <p>
      <span class="emphasis"><em>irise</em></span> -- rise time in seconds. A zero or negative value signifies no rise modification.
    </p>
        <p>
      <span class="emphasis"><em>idur</em></span> -- overall duration in seconds. A zero or negative value will cause initialization to be skipped.
    </p>
        <p>
      <span class="emphasis"><em>idec</em></span> -- decay time in seconds. Zero means no decay. An <span class="emphasis"><em>idec</em></span> &gt; <span class="emphasis"><em>idur</em></span> will cause a truncated decay.
    </p>
        <p>
      <span class="emphasis"><em>ifn</em></span> -- function table number of stored rise shape with extended guard point.
    </p>
        <p>
      <span class="emphasis"><em>iatss</em></span> -- attenuation factor, by which the last value of the <span class="emphasis"><em>envlpx</em></span> rise is modified during the note's pseudo steady state. A factor greater than 1 causes an exponential growth and a factor less than 1 creates an exponential decay. A factor of 1 will maintain a true steady state at the last rise value. Note that this attenuation is not by fixed rate (as in a piano), but is sensitive to a note's duration. However, if <span class="emphasis"><em>iatss</em></span> is negative (or if steady state &lt; 4 k-periods) a fixed attenuation rate of <span class="emphasis"><em>abs</em></span>(<span class="emphasis"><em>iatss</em></span>) per second will be used. 0 is illegal.
    </p>
        <p>
      <span class="emphasis"><em>iatdec</em></span> -- attenuation factor by which the closing steady state value is reduced exponentially over the decay period. This value must be positive and is normally of the order of .01. A large or excessively small value is apt to produce a cutoff which is audible. A zero or negative value is illegal.
    </p>
        <p>
      <span class="emphasis"><em>ixmod</em></span> (optional, between +- .9 or so) -- exponential curve modifier, influencing the steepness of the exponential trajectory during the steady state. Values less than zero will cause an accelerated growth or decay towards the target (e.g. <span class="emphasis"><em>subito piano</em></span>). Values greater than zero will cause a retarded growth or decay. The default value is zero (unmodified exponential).
    </p>
      </div>
      <div class="refsect1">
        <a id="idp101032960"></a>
        <h2>Performance</h2>
        <p>
      <span class="emphasis"><em>kamp, xamp</em></span> -- input amplitude signal.
    </p>
        <p>
      Rise modifications are applied for the first <span class="emphasis"><em>irise</em></span> seconds, and decay from time <span class="emphasis"><em>idur - idec</em></span>. If these periods are separated in time there will be a steady state during which <span class="emphasis"><em>amp</em></span> will be modified by the first exponential pattern. If rise and decay periods overlap then both modifications will be in effect for that time. If the overall duration <span class="emphasis"><em>idur</em></span> is exceeded in performance, the final decay will continue on in the same direction, tending asymptotically to zero.
    </p>
      </div>
      <div class="refsect1">
        <a id="idp101037360"></a>
        <h2>Examples</h2>
        <p>
      Here is an example of the envlpx opcode. It uses the file <a class="ulink" href="examples/envlpx.csd" target="_top"><em class="citetitle">envlpx.csd</em></a>.

      </p>
        <div class="example">
          <a id="idp101039136"></a>
          <p class="title">
            <strong>Example 223. Example of the envlpx opcode.</strong>
          </p>
          <div class="example-contents">
            <p>See the sections <a class="link" href="UsingRealTime.html" title="Real-Time Audio"><em class="citetitle">Real-time Audio</em></a> and <a class="link" href="CommandFlags.html" title="Csound command line"><em class="citetitle">Command Line Flags</em></a> for more information on using command line flags.</p>
            <pre class="programlisting">
<span class="csdtag">&lt;CsoundSynthesizer&gt;</span>
<span class="csdtag">&lt;CsOptions&gt;</span>
<span class="comment">; Select audio/midi flags here according to platform</span>
-odac     <span class="comment">;;;realtime audio out</span>
<span class="comment">;-iadc    ;;;uncomment -iadc if realtime audio input is needed too</span>
<span class="comment">; For Non-realtime ouput leave only the line below:</span>
<span class="comment">; -o envlpx.wav -W ;;; for file output any platform</span>
<span class="csdtag">&lt;/CsOptions&gt;</span>
<span class="csdtag">&lt;CsInstruments&gt;</span>

<span class="ohdr">sr</span> <span class="op">=</span> 44100
<span class="ohdr">ksmps</span> <span class="op">=</span> 32
<span class="ohdr">nchnls</span> <span class="op">=</span> 2
<span class="ohdr">0dbfs</span> <span class="op">=</span> 1


<span class="oblock">instr</span> 1

irise <span class="op">=</span> 0.2
idec  <span class="op">=</span> 0.5
idur  <span class="op">=</span> p3 <span class="op">-</span> idec

ifn <span class="op">=</span> 1
iatss <span class="op">=</span> p5
iatdec <span class="op">=</span> 0.01

kenv <span class="opc">envlpx</span> .6, irise, idur, idec, ifn, iatss, iatdec
kcps <span class="op">=</span> <span class="opc">cpspch</span>(p4)
asig <span class="opc">vco2</span> kenv, kcps
<span class="comment">;apply envlpx to the filter cut-off frequency</span>
asig <span class="opc">moogvcf</span> asig, kcps <span class="op">+</span> (kenv <span class="op">*</span> 8 <span class="op">*</span> kcps) , .5 <span class="comment">;the higher the pitch, the higher the filter cut-off frequency</span>
     <span class="opc">outs</span> asig, asig

<span class="oblock">endin</span>
<span class="csdtag">&lt;/CsInstruments&gt;</span>
<span class="csdtag">&lt;CsScore&gt;</span>
<span class="comment">; a linear rising envelope</span>
<span class="stamnt">f</span> 1 0 129 -7 0 128 1

<span class="stamnt">i</span> 1 0 2 7.00 .1
<span class="stamnt">i</span> 1 + 2 7.02  1
<span class="stamnt">i</span> 1 + 2 7.03  2
<span class="stamnt">i</span> 1 + 2 7.05  3
<span class="stamnt">e</span>
<span class="csdtag">&lt;/CsScore&gt;</span>
<span class="csdtag">&lt;/CsoundSynthesizer&gt;</span>
</pre>
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        <p><br class="example-break" />
    </p>
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      <div class="refsect1">
        <a id="idp101043424"></a>
        <h2>See Also</h2>
        <p>
      <a class="link" href="envlpxr.html" title="envlpxr"><em class="citetitle">envlpxr</em></a>, 
      <a class="link" href="linen.html" title="linen"><em class="citetitle">linen</em></a>, 
      <a class="link" href="linenr.html" title="linenr"><em class="citetitle">linenr</em></a>
    </p>
      </div>
      <div class="refsect1">
        <a id="idp101047456"></a>
        <h2>Credits</h2>
        <p>Thanks goes to Luis Jure for pointing out a mistake with <span class="emphasis"><em>iatss</em></span>.</p>
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